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I would love to hear some explanation from any expert in Paramount P14...

So I was building up my P14 last night.... the BB width measured 68mm which mean English threading. I have both English 68-P-120 and ISO 70P-120 ... Campy BBs.
When I tried to install English BB cups, the threading seems not right, it would not go in. But the ISO cups does.... So I ended up installed ISO BB with 70 spindle. the lockring cup side does stick out 2mm than usual. the chain line is perfect... and spin very smooth...

Also the headset is Italian headset that I installed and fit perfect.
I don't understand... If the BB width measure exactly 68mm then it should be English...

If anyone know why.. I would really appeciate any input..

One thing I thought is that maybe BB threading has been rethread from English to ISO.. but why??

One thing I thought is that maybe BB threading has been rethread from English to ISO.. but why??

That's what I'm thinking, too - maybe a previous owner already had a nice expensive set of parts, and it was cheaper to rethread than to buy a new bottom bracket. Or maybe you've got a team issue frame, which might have been customized to accept a sponsor's parts.

English threading is ISO threading by definition, so either there's a problem in the threading of what you are calling the English-threaded cups or you started to cross-thread when you attempted to install the first cup.

Italian threading for headsets differs from English threading only in the pitch of the threads, not the thread count per mm, so it's not especially surprising that an Italian headset was installed successfully on the Paramount.

Right, he did say it "wouldn't go in", not that it was too small. I'm still not sure if the threads didn't match or the cups bottomed out before they were all the way installed.

See post #4. In other words, there's no problem with the threading in the Paramount's bottom bracket (or fork, for that matter). The problem is that the "English" cup(s) has bad threads; either that or (more likely, in my experience) operator error (starting the cup at an angle so that it started to cross-thread).

As Sheldon B. says above, the original poster should simply install the "English" bottom bracket spindle (the spindle intended for use with 68-mm bottom brackets) to get rid of that extra 2 mm of lockring-side BB cup sticking out and call it a day. While the spindle is out of the frame, I'd also try the "English" cups again if their threads pass close inspection under a strong light.